Central Bureau for Astronomical Telegrams
IAUC 4621: Prob. SUNGRAZING COMETS; AX Per
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Circular No. 4621
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
TWX 710-320-6842 ASTROGRAM CAM Telephone 617-495-7244/7440/7444
MARSDEN or GREEN@CFA.BITNET MARSDEN or GREEN@CFAPS2.SPAN
PROBABLE SUNGRAZING COMETS
Images of two comets rapidly approaching the sun have been found
in data from the Solar Maximum Mission Coronagraph/Polarimeter by
Sharon A. Beck, High Altitude Observatory, Boulder. The following
positions, communicated by O. C. St. Cyr, Chief Observer for the HAO
C/P, have been reduced from her measurements by the SMM Flight
Dynamics Facility at NASA Goddard Space Flight Center:
1987 UT R.A. (1950) Decl.
Oct. 5.90863 12 38 36 - 4 57.0 (SMM 1)
5.97406 12 40 55 - 4 50.4
Oct. 17.81405 13 22 41 - 9 38.4 (SMM 2)
17.87947 13 24 38 - 9 31.2
SMM 1 is very roughly estimated at mag 0 and SMM 2 at mag -2. The
measurements refer to the positions of the 'head', i.e., the sunward end
of the bright cometary tails. The radial distances were estimated to be
accurate to +/- 0.1 solar radius and the position angle to +/- 0.1 deg.
A third image of SMM 2 was obtained on Oct. 17.94491 UT, but the head
was obscured by an electronic artifact that appears in the coronagraph
images. The comets could not be subsequently detected as they receded
from the sun.
Computations by B. G. Marsden, Harvard-Smithsonian Center for
Astrophysics, show it to be very probable that, like the six SOLWIND
comets, the SMM comets belong to the Kreutz group. The positions of
both SMM 1 and SMM 2 can in fact be represented within 2' by the track
of comet 1843 I. A somewhat better fit, leaving residuals of no more
than 0'.8, is given by the Kreutz-type orbital elements Peri. = 81.0,
Node = 1.2, i = 144.3 (equinox 1950.0), q = 0.0057 AU, with the
perihelion times T = 1987 Oct. 6.07 and 1987 Oct. 18.01 ET for SMM 1 and
SMM 2, respectively.
AX PERSEI
Visual magnitude estimates: Mar. 27.7 UT, 9.0 (A. Mizser
[spelled incorrectly on IAUC 4593], Budapest, Hungary); May 22.07,
8.7 (S. Korth, Monheim, West Germany); June 2.02, 9.0 (P. Schmeer,
Bischmisheim, West Germany); 5.03, 9.0 (Schmeer); 11.06, 9.0
(Schmeer); 15.05, 9.0 (Schmeer); 19.06, 9.1 (Schmeer);
24.07, 9.2 (Schmeer).
1988 July 1 (4621) Brian G. Marsden
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